Imaging device

ABSTRACT

An imaging device includes an imaging sensor that outputs an imaging signal representing a sequence of frame images of a photographic subject. A buffer memory temporarily stores data of the sequence of frame images from the imaging signal. A release switch is actuated by a user to output an image-taking signal. A controller, upon receipt of the image-taking signal from the release switch: (i) generates moving image data from at least some of the plurality of frame images stored in the buffer memory, (ii) generates at least one piece of still image data based on at least one frame image of the plurality of frame images stored in the buffer memory, and (iii) associates the moving image data with the still image data and records the moving image data and the still image data in a recording medium.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 15/214,850filed on Jul. 20, 2016, which is a continuation of U.S. patentapplication Ser. No. 13/796,742 filed Mar. 12, 2013, which in turn is acontinuation of U.S. patent application Ser. No. 13/093,557 filed Apr.25, 2011 (now U.S. Pat. No. 8,422,868), the disclosure of which isincorporated by reference herein in its entirety. The disclosure of thefollowing priority application also is incorporated hereby reference inits entirety:

Japanese Patent Application No. 2010-119424, filed on May 25, 2010.

TECHNICAL FIELD

The present invention relates to an imaging device that can record amoving image.

BACKGROUND ART

A recording device is proposed in which a moving image starts to betemporarily stored when moving image-incorporated still image capturingmode is set; and a captured still image is recorded and a moving imageis generated from any one of the following moving images and recordedwhen a shutter button is pressed: a moving image that has beentemporarily stored before the still image is captured, a moving imageconverted from the captured still image, and a moving image capturedafter the shutter button is pressed (refer to, for example,WO2006/028172).

SUMMARY OF INVENTION

However, in regard to known imaging devices equipped with the recordingdevice disclosed in WO2006/028172, no technology is disclosed in which amoving image having an impressive digital video effect such as a slowmotion moving image where a subject appears to move more slowly thanactual movement is captured in synchronization with the timing at whichthe still image is captured, and the moving image and the still imageare associated with each other and recorded.

An object of the invention is to provide an imaging device capable ofcapturing a slow motion moving image with high resolution and extremeprecision in an automatic manner, in relation with timing of capturing astill image with high resolution and extreme precision.

An imaging device according to the invention includes a storage unitthat sequentially stores a plurality of frame images based on an imagingsignal from an imaging sensor that images light from a subject, a movingimage data generation unit that generates slow motion moving image datato be played at a second frame rate lower than a first frame rate thatrepresents the number of the frame images stored per unit time in thestorage unit, based on the plurality of frame images stored in thestorage unit for a predetermined time period, a still image datageneration unit that generates at least one piece of still image databased on at least one frame image of the plurality of frame imagesstored during the predetermined time period in the storage unit, and arecord control unit that associates the slow motion moving image datagenerated by the moving image data generation unit with the still imagedata generated by the still image data generation unit and records themoving image data and the still image data in a recording medium.

According to the imaging device of the invention, it is possible tocapture the slow motion moving image with high resolution and extremeprecision and to capture the still image with high resolution andextreme precision in parallel, at synchronized timing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a system configuration of anelectronic camera according to an embodiment.

FIG. 2 is an explanatory diagram illustrating a frame rate for storing aslow motion moving image in a buffer memory and a frame rate forrecording the slow motion moving image in a recoding medium at the timeof capturing the slow motion moving image.

FIG. 3 is a flowchart illustrating a process pertained when the slowmotion moving image and a still image are captured in the electroniccamera according to the embodiment.

FIG. 4 is a diagram illustrating an exemplary display on a display unit.

FIG. 5 is a diagram illustrating an exemplary indication by anindicator.

FIG. 6 is an explanatory diagram illustrating another example of theframe rate for recording the slow motion moving image in the recordingmedium at the time of capturing the slow motion moving image.

DESCRIPTION OF EMBODIMENTS

Hereafter, an electronic camera as an imaging device according to anembodiment of the present invention will be described with reference tothe accompanying drawings. FIG. 1 is a block diagram illustrating asystem configuration of an electronic camera 2 according to a firstembodiment. As illustrated in FIG. 1, the electronic camera 2 isconfigured by a microprocessor and the like. The electronic camera 2includes a control unit 4 that collectively controls over respectiveunits of the electronic camera 2. The control unit 4 is connected withan imaging sensor 6, a buffer memory 8, a recording medium 10, a displayunit 12, an operation unit 14, and a detection unit 16.

The imaging sensor 6 is configured by a CCD, CMOS or the like, andimages light from a subject through an image-capturing lens (not shown).The control unit 4 acquires image data based on an imaging signal thatis a digital signal obtained by converting an analog signal output fromthe imaging sensor 6 using an A/D converter (not shown).

The buffer memory 8 temporarily stores image data produced based on theimaging signal from the imaging sensor 6. In particular, when theelectronic camera 2 is set, for example, to slow motion moving imagecapturing mode or the like in which a slow motion moving image (to bedescribed below and also referred to as a slow moving image hereinafter)is captured, the buffer memory 8 sequentially stores a plural number ofpieces of image data based on the imaging signal output from the imagingsensor 6 in synchronization with a moving image cycle (60 fps or thelike), that is, a plurality of frame images constituting the slow movingimage. In this case, the frame images, each having the number of pixelsmatching or exceeding the standard (1280×720 pixels or more) of highdefinition television (HDTV), that is, so-called high resolution frameimages are sequentially stored in the buffer memory 8 in a first-infirst-out (FIFO) manner.

More specifically, in a case where the buffer memory 8 has a storagearea that is allowed to store, for example, n (n is a natural number)frame images, as illustrated in FIG. 2(a), the control unit 4 performscontrol such that a first frame image F1 obtained through a firstacquisition, a second frame image F2 obtained through a secondacquisition, . . . , and an n-th frame image Fn obtained through an n-thacquisition are sequentially stored in the buffer memory 8. In a casewhere a subsequent frame image Fn+1 is output from the imaging sensor 6after n frame images F1 to Fn are stored in this way, the oldest frameimage F1 is removed from the buffer memory 8 and the newest frame imageFn+1 is stored instead. Whenever a subsequent frame image is output fromthe imaging sensor 6, a process of removing the oldest frame image andstoring the newest frame image is repeatedly performed.

That is, the buffer memory 8 includes n addresses (storage areas tosequentially store the frame images), and stores sequentially the firstframe image F1 in an address of address number (n−1), the second frameimage F2 in an address of address number (n−2), . . . , and the n-thframe image Fn in an address of address number 0. That is, the frameimages F1 to Fn are stored in all of the n addresses, the subsequentframe image Fn+1 is output, and the frame image (that is, the oldestframe image) F1 in the address of address number (n−1) is deleted. Then,the respective frame images F2 to Fn are shifted from the addresses ofaddress number (n−2) to address number 0 so as to be stored in theaddresses of address number (n−1) to address number 1, respectively, andthe (n+1)-th frame image (that is, the newest frame image) Fn+1 isstored in the address of address number (0). Accordingly, the newestframe image is always stored in the address of address number (0), andthe address with the greater address number stores the older frameimage. The address with address number 0 stores the newest frame imageat all times.

The recording medium 10 is a potable type recording medium that isremovably installed in a card slot (not shown) provided in theelectronic camera 2. For example, a CF card, an SD card, a smart media,or the like is used as the recording medium. In the recording medium 10,moving image data and slow moving image data are recorded. The movingimage data and the slow moving image data are produced by subjectingeach of the frame images stored in the buffer memory 8 to a resizingprocess (resizing from a high resolution to a low resolution) to achievea resolution suitable for a moving image, which is performed by areduction circuit (not shown) in the control unit 4, a moving-imageimage process performed by a moving image signal processing circuit (notshown) in the control unit 4, and a moving image compression processperformed by a moving image compression circuit (not shown) in thecontrol unit 4. In the recording medium 10, information related toimage-capturing and still image data are also recorded. The still imagedata is obtained by subjecting the frame image stored in the buffermemory 8 to a still-image image process performed by a still imagesignal processing circuit (not shown) in the control unit 4 and a stillimage compression process performed by a still image compression circuit(not shown) in the control unit 4.

The display unit 12 is configured by a monitor including an LCD and thelike provided on the rear surface of the electronic camera 2, or an EVFor the like including an LCD and the like. The display unit 12 displaysa through image based on the imaging signal from the imaging sensor 6, amoving image based on the moving image data recorded in the recordingmedium 10, a slow moving image based on the slow motion moving imagedata (hereinafter, referred to as slow moving image data), a still imagebased on the still image data, and information related to theimage-capturing. The operation unit 14 is configured by including apower supply switch operated for turning on/off the power supply of theelectronic camera 2, a command dial operated for setting image-capturingmode such as moving image capturing mode for capturing a moving image orslow motion moving image capturing mode for capturing a slow movingimage, a release button operated for entering instructions such as aninstruction to start capturing of a moving image or a still image, amenu button operated for displaying menu items or the like on thedisplay unit 12, a cross key operated for selection of a menu item orthe like or for setting various conditions, an OK button operated forconfirmation of the operation such as selection of a menu item orsetting of various conditions, and the like.

The detection unit 16 is configured by including an attitude sensor andthe like and detects information related to a change in the attitude ofthe electronic camera 2 relative to a subject at the time of capturingthe slow moving image in the electronic camera 2. The control unit 4controls an ending time of the capturing of the slow moving image basedon the detection result from the detection unit 16. Instead of includingthe attitude sensor, the detection unit 16 may be configured byemploying a structure that detects information related to a change inthe attitude of the electronic camera 2 by detecting a change inmovement of a subject, based on at least two frame images having aresolution suitable for the detection of attitude change of theelectronic camera 2, at first which are produced based on the imagingsignal from the imaging sensor 6 and then subjected to a resizingprocess (resizing from a high resolution to a low resolution) performedby the reduction circuit (not shown) in the control unit 4.

In the electronic camera 2 according to this embodiment, the slow movingimage data that is to be played at a second frame rate lower than afirst frame rate that represents the number of frame images being storedper unit time in the buffer memory 8 after being output from the imagingsensor 6 is generated. The still image data is generated based on atleast one frame image out of the plurality of frame images thatconstitute the slow moving image data. The generated slow moving imagedata and the still image data can be recorded in the recording medium 10in association with each other. Hereinafter, a process performed at thetime of capturing the slow moving image and the still image in theelectronic camera 2 according to the embodiment will be described withreference to a flowchart illustrated in FIG. 3.

In this embodiment, the slow moving image data is generated based on aplurality of frame images stored in the buffer memory 8 for a timeperiod from a time at which the frame image to become the still imagedata is stored in the buffer memory 8 to the beginning of a firstpredetermined time period, and a plurality of frame images stored in thebuffer memory 8 for a time period, that is, until the end of a secondpredetermined time period after the frame image to become the stillimage is stored in the buffer memory 8. That is, the slow moving imagedata is generated based on the plurality of frame images stored in thebuffer memory 8 during a predetermined time period (the firstpredetermined time period+the second predetermined time period), and thestill image data is generated based on the frame image stored in thebuffer memory 8 at the ending time of the first predetermined timeperiod (that is, the beginning time of the second predetermined timeperiod). Furthermore, the predetermined time period (for example, 1second or the like), the first predetermined time period (for example,0.6 second or the like), and the second predetermined time period (forexample, 0.4 second or the like) are set in advance and stored in amemory (not shown) in a rewritable manner. In other words, the slowmoving image data is generated based on the plurality of frame imagesstored from the beginning of the first predetermined time period, whichbegins before the frame image to become the still image data is storedin the buffer memory 8, until the end of the second predetermined timeperiod, which ends after the frame image to become the still image isstored in the buffer memory 8.

First, when a user operates the command dial to set the slow motionmoving image capturing mode, the control unit 4 switches to the slowmotion moving image capturing mode for capturing the slow motion movingimage and the still image associated with the slow motion moving image.Then, it is determined whether or not the user has half-pressed therelease button (Step S10). When it is determined that the release buttonis half-pressed in Step S10, the control unit 4 determines that aninstruction to prepare generation of the still image data and aninstruction to generate the slow moving image data are given.Accordingly, as shown in FIG. 4, the control unit 4 performs controlsuch that the display unit 12 displays the through image 20 and theindicator 22 thereon, and a focus lens (not shown) or the like is drivento move a focus position toward a main subject for the main subject inthe through image 20 to be on focus. Then, it is determined whether ornot the main subject is on focus (Step S11). The indicator 22 has afunction of indicating to the user where the current time point iswithin the time span between the beginning and end (that is, over theentire period during which the slow moving image is generated) of thepredetermined time period (in other words, indicating where the currenttime point is within the time span between the beginning and end of thefirst predetermined time period and where the current time point iswithin the time span between the beginning and end of the secondpredetermined time period). Referring to FIG. 4, a bar 22 c (describedbelow, see FIG. 5) inside a frame 22 a of the indicator 22 is notdisplayed. No display of the bar 22 c means an operation stage beforethe beginning of the first and second predetermined time periods. A mark22 b represents the ending time of the first predetermined time period(the beginning time of the second predetermined time period), that is,the mark 22 b means that the full-pressing operation of the releasebutton in Step S13 to be described below is executed. The indicator 22will be described below in detail.

When it is determined that the main subject is on focus in Step S11 (Yesin step S11), the control unit 4 pertains control such that thecapturing of the slow moving image is started, that is, the bufferinginto the buffer memory 8 and the indication of the current time point bythe indicator 22 are started (step S12). Specifically, as describedabove, the control unit 4 performs control such that the plurality offrame images F1, . . . , and Fn . . . (see FIG. 2) produced based on theimaging signal, which is output from the imaging sensor 6 insynchronization with the moving image cycle, start to be stored in thepredetermined addresses in the buffer memory 8. Next, when the bufferinginto the buffer memory 8 is started, the control unit 4 starts controlof causing the indicator 22 to indicate the progress of buffering, thatis, which time point of buffering between the beginning and end of thepredetermined time period (the first predetermined time period) is beingexecuted at the current time point. That is, at the time prior to thebeginning of the predetermined time period (the first predetermined timeperiod), as shown in FIGS. 4 and 5(a), nothing is displayed inside theframe 22 a of the indicator 22. However, when the buffering is started,as shown in FIG. 5(b), the display of the bar 22 c is started from theleft end of the frame 22 a. As the frame images stored in the buffermemory 8 increase in number (with time), as shown in FIG. 5(c), the bar22 c extends toward the right side of the frame 22 a.

In this embodiment, when the release button is full-pressed by the user(Yes in Step S13 to be described below), the still image data isgenerated based on the frame image that is based on the imaging signaloutput from the imaging sensor 6. Accordingly, after n frame images arestored in the buffer memory 8 until the release button is full-pressedby the user from the time at which the first predetermined time periodends, a process is repeatedly performed in which the oldest frame imagein the buffer memory 8 is deleted each time the frame image is output,and the output frame image (the newest frame image) is stored in thebuffer memory 8. In this case, the bar 22 c inside the frame 22 a doesnot show any change as being in the state illustrated in FIG. 5(c). Thatis, the bar 22 c extends up to the position of the mark 22 b thatrepresents the time (the end of the first predetermined time period andthe beginning of the second predetermined time period) at which thestill image is captured, but does not extend during a period in whichthe release button is not full-pressed by the user.

Next, in the middle of the process in which storage of the frame imageinto the buffer memory 8 is repeatedly performed after the firstpredetermined time period has elapsed, the control unit 4 determineswhether or not the release button is full-pressed by the user (StepS13). When it is determined that the release button is full-pressed bythe user in Step S13, the control unit 4 determines that a still imagecapturing instruction to generate the still image data is input. In thiscase, the control unit 4 causes the second predetermined time period(ending the counting for the first predetermined time period) to beginto elapse, and causes the bar 22 c to extend toward the right side ofthe frame 22 a with time as illustrated in FIG. 5(d). In this way, bydisplaying the bar 22 c that indicates where a current time point isbetween the beginning and end of the predetermined time period (thesecond predetermined time period) on the display unit 12, it is possibleto indicate to the user that the capturing of the slow moving image isnot completed. Next, the control unit 4 acquires information related tothe change in the attitude of the electronic camera 2 relative to themain subject detected by the detection unit 16, and determines whetheror not the acquired change in the attitude of the electronic camera 2 isequal to or more than a predetermined threshold value (Step S14). Thatis, when it is determined that the user has full-pressed the releasebutton or the like for example, it is further determined whether or notthe attitude of the electronic camera 2 which is posed during theimage-capturing is considerably changed, for example, to an attitude ofthe electronic camera 2 at the state of not capturing. The predeterminedthreshold value is set in advance to an appropriate value and stored ina memory (not shown) or the like.

When it is determined that the change in the attitude of the electroniccamera 2 is not equal to or more than the predetermined threshold valuein Step S14 (No in Step S14), the control unit 4 determines whether ornot the predetermined time period (the second predetermined time period)has elapsed (Step S15). That is, it is determined whether or not thestorage of the frame images necessary to generate the slow moving imagedata into the buffer memory 8 is completed after the release button isfull-pressed (that is, after the entering of the still image capturinginstruction). When it is determined that the predetermined time period(the second predetermined time period) has not yet completely elapsed inStep S15 (No in Step S15), the control unit 4 returns the process toStep S14.

On the other hand, when it is determined that the predetermined timeperiod (the second predetermined time period) has completely elapsed inStep S15 (Yes in Step S15), the control unit 4 determines that thestorage of n frame images necessary to generate the slow moving imagedata into the buffer memory 8 is completed, and thereby ends thebuffering into the buffer memory 8 and the indication of the currenttime point by the indicator 22 (Step S16). At this time, as illustratedin FIG. 2(a), n−p (p is a natural number, n>p) frame images, F2 to F5 .. . , have been stored in the buffer memory 8 over a period from a timeprior to the input time TS of the still image capturing instruction to atime prior to the beginning of the first predetermined time period, andp frame images, . . . Fn and Fn+1, have been stored over a period fromthe input time TS of the still image capturing instruction to the endingtime of the second predetermined time period. In Step S17 describedlater, the slow moving image data is generated based on the n frameimages F2 to Fn+1. FIG. 5(e) illustrates the state of the bar 22 cinside the frame 22 a of the indicator 22 after the predetermined timeperiod (the second predetermined time period) has completely elapsed.

Further, when it is determined that the change in the attitude of theelectronic camera 2 is equal to or more the predetermined thresholdvalue in Step S14 (Yes in Step S14), the control unit 4 determines thatthe attitude of the electronic camera 2 is considerably changed, andends the buffering into the buffer memory 8 and the indication of thecurrent time point by the indicator 22 even in a case where thepredetermined time period (the second predetermined time period) has notyet elapsed (Step S16). That is, even in a case where the bar 22 cinside the frame 22 a of the indicator 22 is not in the state of FIG.5(e) but in the state of FIG. 5(d), the time at which it is determinedthat the change in the attitude of the electronic camera 2 is equal toor more than the predetermined threshold value is used as the end pointof the predetermined time period (the second predetermined time period).In this case, the slow moving image data is generated in Step S17 basedon the frame images stored in the buffer memory 8, where the frameimages include n−p (p is a natural number, n>p) frame images F2 to F5 .. . stored during a period from a time prior to the input time TS of thestill image capturing instruction to a time prior to the beginning ofthe first predetermined time period, and frame images, of which thenumber is smaller than p, stored during a period from the input time TSof the still image capturing instruction to the time at which it isdetermined that the change in the attitude of the electronic camera 2 isequal to or more than the predetermined threshold value, that is, theframe images F2 to F5 . . . that are smaller in number than n.

Next, the control unit 4 performs a slow moving image data generatingprocess and a still image data generating process based on the pluralityof frame images stored in the buffer memory 8 (Step S17). The slowmoving image data generating process will be described first. Thecontrol unit 4 reads the frame images F2 to F5 . . . out of the buffermemory 8 at a second frame rate (for example, 24 frames/second or thelike which is equal to 1/2.5, that is, 0.4, of a first frame rate) lowerthan the first frame rate (for example, 60 frames/second or the like)which is the same as a frame rate (image-capturing frame rate) at whichthe frame images are output from the imaging sensor 6. That is, theframe image F2 stored in the buffer memory 8 at a time T1 (for example1/60 second or the like) as illustrated in FIG. 2(a) is read out of thebuffer memory 8 at a time T2 (for example, 1/24 second) as illustratedin FIG. 2(b). Then the read frame images F2 to F5 . . . are subjected toa resizing process (resizing from a high resolution to a low resolution)of resizing the frame image to have a resolution suitable for a movingimage, performed by the reduction circuit (not shown) in the controlunit 4, and the moving-image image process (inclusive of the imagecompression process), performed by the moving image signal processingcircuit (not shown) in the control unit 4 so as to generate the slowmoving image data. The value of the second frame rate is set in advance,and stored in a memory (not shown) in a rewritable manner.

Next, the still image data generating process will be described. Thecontrol unit 4 reads the frame images stored in the buffer memory 8 atthe time TS, at which the still image capturing instruction is input,out of the buffer memory 8. Next, the still image data is generated bysubjecting the read frame image to the still-image image process(inclusive of the still image compression process) performed by thestill image signal processing circuit (not shown) provided separatelyfrom the moving image signal processing circuit in the control unit 4.In this embodiment, since the frame images, each having pixels more thanthose required for the standard of HDTV, that is, high resolution frameimages are stored in the buffer memory 8, it is possible to obtain thestill image data of high resolution. In addition, the number of pixelsof the generated still image data is larger than that of the generatedslow moving image data.

Next, when an instruction to display the slow moving image and the stillimage on the display unit 12 is entered via the operation unit 14 by theuser, the control unit 4 causes the display unit 12 to display thepreview of the slow moving image that is based on the slow moving imagedata generated in Step S17. Then the control unit 4 causes the displayunit 12 to display the preview of the still image that is based on thestill image data generated in Step S17 for several seconds (which areset in advance) (Step S18).

Next, the control unit 4 causes the display unit 12 to display aselection screen that allows the user to select whether or not to recordat least either one of the slow moving image data and the still imagedata generated in Step S17 in the recording medium 10 before recordinginto the recording medium 10 is started. The selection screen includes adescription informing that one of the items “record only slow movingimage data”, “record only still image data”, “record both slow movingimage data and still image data”, and “record neither slow moving imagedata nor still image data” can be selected, icons, and the like. Thecontrol unit 4 determines whether or not the user has selected to recordat least any one of the slow moving image data and the still image datain the recording medium 10 using the selection screen (Step S19).

When it is determined that the user has selected to record at leasteither one of the slow moving image data and the still image data in therecording medium 10 in Step S19 (Yes in Step S19), that is, when any oneof the items “record only slow moving image data”, “record only stillimage data”, and “record both slow moving image data and still imagedata” is selected by the user, the control unit 4 records at least anyone of the slow moving image data and the still image data in therecording medium 10 according to the selection by the user (Step S20).Specifically, when the item “record only slow moving image data” isselected, only the slow moving image data is recorded (the still imagedata is deleted). When the item “record only still image data” isselected, only the still image data is recorded (the slow moving imagedata is deleted). When the item “record both slow moving image data andstill image data” is selected, both of the slow moving image data andstill image data are recorded. In a case where the slow moving imagedata is to be recorded in the recording medium 10, the slow moving imagedata generated in Step S17 is subjected to the moving image compressionprocess performed by the moving image compression circuit (not shown) inthe control unit 4 and the compressed slow moving image data is recordedin the recording medium 10. In a case where the still image data is tobe recorded in the recording medium 10, the still image data generatedin Step S17 is subjected to the still image compression processperformed by the still image signal processing circuit (not shown) inthe control unit 4 and then the compressed still image data is recordedin the recording medium 10. In a case where both of the slow movingimage data and the still image data are to be recorded in the recordingmedium 10, both data are recorded after being associated with each other(after being added with information (date and time at which an image iscaptured, identification number, or the like) indicating the associationbetween both data).

Since the slow moving image data and the still image data are recordedin association with each other, for example, it is possible to displayinformation informing that the still image linked to the slow movingimage exists, during the playing of the slow moving image and to displayintonation informing that the slow moving image linked to the stillimage exists, during the display of the still image. In addition, whendisplaying a reduced image (thumbnail image) based on reduction imagedata of the still image that is generated at the time of generating thestill image data and recorded in a state of being added to the stillimage data, it is possible to display information informing that therelated slow moving image exists. Further, when the user enters aninstruction to play the related slow moving image (or still image) usingthe operation unit 14 during the playing of the still image (or the slowmoving image), the slow moving image (or the still image) can be easilyplayed.

On the other hand, when it is determined that the user has selected notto record at least one of the slow moving image data and the still imagedata in the recording medium 10 in Step S19 (No in Step S19), that is,when it is determined that the user has selected the item “recordneither slow moving image data nor still image data”, the control unit 4deletes both of the slow moving image data and the still image datagenerated in Step S17 without recording them in the recording medium 10in accordance with the selection of the user.

In Step S18, when displaying the selection screen for selecting whetheror not at least any one of the slow moving image data and the stillimage data is to be recorded in the recording medium 10 after the slowmoving image and the still image are displayed for preview on thedisplay unit 12, or after displaying the selection screen, the inventionmay employ a structure that can change the value of the second framerate and generate the slow moving image again at the changed secondframe rate. This case effectively applies to a case in which the userwants to further slow down or slightly increase the playing speed of theslow moving image which is to be displayed after the user has watchedthe image once through the preview. Specifically, the control unit 4returns the process to Step S17 when the value of the second frame rateis changed by the user through the operation of the operation unit 14,so that a series of frame images stored in the buffer memory 8 is readagain at the changed second frame rate, and the slow moving image isplayed based on the frame images that are read. After that, the slowmoving image is displayed on the displayed unit 12 at the changed framerate for preview, and a confirmation screen (selection screen) forconfirming whether to record the slow moving image data having thechanged frame rate in the recording medium 10 is displayed on thedisplay unit 12. When the user performs an operation of confirming therecord of the changed slow moving image using the operation unit 14, theslow moving image data generated with use of the changed second framerate is recorded in the recording medium 10.

According to the electronic camera 2 of the embodiment, it is possibleto capture a slow moving image having an impressive video effect, highresolution, and extreme precision, and to capture a still image havinghigh resolution and extreme precision in the middle of capturing theslow moving image. That is, since the frame images that constitute aslow moving image are stored with a high resolution in the buffer memory8, it is possible to generate the slow moving image data with highresolution and extreme precision. In addition, since the still imagedata is generated based on the high resolution frame image, it ispossible to generate the still image data with high resolution andextreme precision (for example, the still image data having a resolutionhigher than that of the slow moving image data). Furthermore, since itis possible to indicate to a user a time period (predetermined timeperiod) during which the frame images for generating the slow movingimage data are being buffered using the indicator 22, the user canquickly check whether or not the slow moving image is being captured.Accordingly, it is possible to suppress a significant change in theattitude of the electronic camera 2 relative to the subject in themiddle of capturing the slow moving image and thus it is possible togenerate the slow moving image data with good precision. Moreover, it ispossible to control the ending time of the predetermined time period(the second predetermined time period) based on the detection resultfrom the detection unit 16, and to suspend the buffering of the frameimages when the attitude of the electronic camera 2 is considerablychanged. Accordingly, it is possible to generate the slow moving imagedata with good precision which is obtained before the attitude of theelectronic camera 2 is considerably changed.

In the above embodiment, when the predetermined time period (the secondpredetermined time period) that is set in advance has elapsed, or whenthe change in the attitude of the electronic camera 2 relative to themain subject is equal to or more than the threshold value, the bufferinginto the buffer memory 8 and the indication of the current time point bythe indicator 22 end. However, a configuration may be employed in whichthe buffering into the buffer memory 8 and the indication of the currenttime point by the indicator 22 end when it is determined that therelease button is full-pressed in a state in which the frame images arebeing sequentially stored in the buffer memory 8.

In the above embodiment, a piece of still image data is generated basedon one frame image stored in the buffer memory 8 when it is determinedthat the release button is full-pressed, but two or more pieces of stillimage data may be generated based on two or more frame images.Alternatively, the still image data may be generated based on the frameimage stored in the buffer memory 8 before or after it is determinedthat the release button is full-pressed. In addition, the still imagedata may be generated based on the frame image stored in the buffermemory 8 when the release button is not full-pressed (for example, in acase where a best shot is made when the release button is notfull-pressed or the like). In this case, the frame images stored in thebuffer memory 8 are displayed on the display unit 12 for example so thatthe user can select at least one frame image to be recorded as the stillimage data, and the still image data is generated based on the selectedframe image.

In the above embodiment, the slow moving image data is generated byreading, at the second frame rate, the frame images which are stored atthe first frame rate in the buffer memory 8. However, a configurationmay be employed in which the moving image data is generated by readingthe frame images at the first frame rate and the slow moving image datais generated by adding information instructing to play back the movingimage at the second frame rate to the generated moving image data.

In the above embodiment, the frame images F2, . . . , Fn+1 stored in thebuffer memory 8 for the time period T1 as illustrated in FIG. 2(a) areread out of the buffer memory 8 for the time period T2 in anon-interlace manner as illustrated in FIG. 2(b). However, the inventionmay be configured such that the frame images F2 to Fn+1 may be read inthe interlace manner. For example, as shown in FIG. 6, one field(hereinafter, referred to as a first field) F2E obtained by diving theframe image F2 into two fields is read for the time period T1 and thenthe other field (hereinafter, referred to as a second field) F2O is readfor the time period T1. The first field F2E is a field configured byonly even-numbered lines of the frame image F2 for example, and thesecond field F2O is a field configured by only odd-numbered lines of theframe image F2. Subsequently, as shown in FIG. 6, after the first fieldF2E is read again for the time period T1, one field F3E of the frameimage F3 obtained by diving the frame image F3 into two fields is readfor the time period T1 and then the other field F3O is read for the timeperiod T1. Through the similar reading operation, that is, as shown inFIG. 6, a field F4E of the frame image F4 obtained by diving the frameimage F4 into two fields is read, the other field F4O is read, the fieldF4E is read again, and a field F5E obtained by diving the frame image F5into two fields is read, and the other field F5O of the frame image isread. In this way, the reading operation is repeated sequentially forthe frame images. As a result, it is possible to generate the slowmoving image data at the second frame rate that is 1/2.5 (that is, 0.4)of the first frame rate.

The above-described embodiment is provided for easy understanding of theinvention and thus is not construed to limit the invention. Accordingly,each element disclosed in the above embodiment includes designmodifications and equivalents within the technical scope of theinvention.

1. An electronic device comprising: an imaging sensor that images asubject and sequentially outputs image data; a buffer memory thattemporarily stores data of the sequence of frame images from the imagingsignal; a controller that receives an imaging instruction; and arecording controller that records moving image data generated, when theimaging instruction is received by the controller, based on (i) imagedata output by imaging performed by the imaging sensor before receivingthe imaging instruction and (ii) image data output by imaging performedby the imaging sensor after receiving the imaging instruction, to arecording medium.
 2. The electronic device according to claim 1, furthercomprising: a setting portion that sets a shooting mode, and a generatorthat generates the moving image data and still image data when aspecified shooting mode is set by the setting portion, wherein therecording controller records the moving image data generated by thegenerator.
 3. The electronic device according to claim 1, wherein therecording controller records the moving image data generated based on(i) first image data generated by imaging performed by the imagingsensor during a first specified time before receiving the imaginginstruction and (ii) second image data generated by imaging performed bythe imaging sensor during a second specified time after receiving theimaging instruction.
 4. The electronic device according to claim 3,wherein the recording controller records still image data generatedbased on either (i) first image data generated by imaging performed bythe imaging sensor during the first specified time before receiving theimaging instruction or (ii) second image data generated by imagingperformed by the imaging sensor during the second specified time afterreceiving the imaging instruction and moving image data.